Warboss Grimskull (Warhammer 40K Space Marine)
Choose your weapon load out carefully before entering the arena. This fight consists of two phases: the "ground phase" (arguably the most difficult phase to survive), and the "ranged phase". During the ground phase Boss Grimskull charges at you, sweeps at you with his power claw, shoots with his attached twin-linked shoota and lobs grenades. He will be reinforced twice by a horde of Orks to help harass you. Then, once he's sustained enough damage, he will jump to a ledge from which he will continue to lob grenades and shoot rockets while Orks and Squigs intermittently drops down to attack you.Depending on your fighting stance of choice (melee or ranged), there are certain tactics to follow for when you finally take on the Warboss. While you can take him on with a Thunder Hammer during the ground phase, timing is everything, especially since the Thunder Hammer's rate of attack is slow and the Warboss can kill you with two or three direct melee attacks. The Hammer does deliver a devastating blow, especially with the attack-attack-attack-stun chain, and it helps to clear the massing Ork Boyz at the same time, quite effectively. However, this means you'll have to come up close to him and chain your attacks just after you dodged a charge or attack from him. For a player focusing on melee attacks, regardless of weapon choice, the Ork Boyz he brings into the fight can be killed to build up the Fury bar, and once it is full, unleash your Fury to quickly batter the Warboss down. Alternatively the Meltagun works very well since you can run around the Warboss and shoot him, dealing massive damage without coming too close. Regardless of your chosen weapons, the biggest openings are when you successfully dodge out of the way of his charge and he runs past, and when you manage to avoid his fire when he uses his ranged weaponry; use these openings to deal out as much punishment as you can. Once he jumped to the ledge, entering the ranged phase, the best weapon to use is probably the Vengeance Launcher since the explosive damage of the Vengeance mines can also take out any Orks and Squigs around the Warboss. Rapid fire weapons such as the standard Bolter are completely viable, though you will need to be attentive and quick; try and shoot the Bomb Squigs just before they drop down, so that their explosions also damage the Warboss. Between Squig waves, shoot directly at Grimskull, going for the head if possible. If you went in with the Thunder Hammer, you will indeed be limited to the Bolter at this stage. Just move or roll to dodge his ranged attacks as needed, clear the few Orks that drop down, performing Executions if necessary, and shoot the Squigs while they're still around the Boss' legs. Stay on your toes, rinse and repeat, and he will eventually stagger and fall off the ledge. Walk up to the battered Warboss and press Execute to finish the fight. See: Warhammer 40K Space Marine